Akademik Veri Yönetim Sistemi
Veterinary Research Forum, cilt.17, sa.2, ss.89-94, 2026 (SCI-Expanded, Scopus)
The aim of this study was to investigate the effects of post-partum (PP) periods of different lengths on super-stimulatory and super-ovulatory responses, as well as the number and quality of embryos in Simmental cows. Fifty cows were divided into five groups based on their PP days, including 50-60 days (n = 5), 61-90 days (n = 17), 91-120 days (n = 9), 121-150 days (n = 9), and 151-420 days (n = 10). On a random day of the estrous cycle, all follicles larger than 5.00 mm on the ovaries were aspirated and a progesterone-releasing device was inserted into the vagina of all donors. Approximately 36 hr after follicle aspiration, all cows were administered 500 µg of follicle-stimulating hormone in decreasing doses, twice daily for 6 days. Ovaries were evaluated using trans-rectal ultrasonography during human chorionic gonadotropin treatment and after embryo collection to assess follicles and corpora lutea, respectively. Super-stimulatory and super-ovulatory responses, as well as embryo yield and quality were found to be similar among cows in the PP days groups of 61-90, 91-120, 121-150, and 151-420. However, the embryo recovery rate and mean number of transferable and freezable embryos were adversely affected in cows at 50-60 days PP. The findings of our study suggested that day 60 PP served as a threshold for in vivo embryo production in Simmental cows.